Iron electrolysis‐assisted peroxymonosulfate chemical oxidation for the remediation of chlorophenol‐contaminated groundwater

Electrolysis with an iron anode is a novel way to provide ferrous activators for chemical oxidation. The objective of this study is to evaluate the performance of peroxymonosulfate (PMS) for chlorophenol destruction when compared with H2O2 and persulfate (PS), and to see whether the electrolysis mode facilitates the buildup of conditions that favor the activation of PMS and removal of chlorophenols.Ferrous species can effectively activate the PMS over a wide pH range. In comparison with H2O2 and PS, PMS is less sensitive to the solution's pH and possesses stronger oxidation capability at alkaline pHs. The optimal molar ratio of PMS to Fe(II) activator is 1:1 for the destruction of 2,4-dichlorophenol (2,4-DCP). The column experiments show that an acidic zone developed downstream from the anode is favorable to maintain ferrous ions and subsequent activation of PMS. The reactivity of the PMS can be manipulated by varying the electrical currents, and the process demonstrates effectiveness for treating organic contaminants. 2,4-DCP contaminated groundwater shows decreased biotoxicity after the chemical oxidation process without considering the residual PMS.Iron electrolysis-assisted peroxymonosulfate chemical oxidation can effectively treat the 2,4-dichlorophenol and mixtures of organic contaminants. This process can be engineered as an in situ chemical oxidation method for groundwater remediation.